There are two major goals in the design of projectors: On the one hand size and costs of the components are to be reduced and on the other hand the lumen output should be increase. Therefore, light sources in projectors emit light with extremely high luminance. This allows the use of small image generators and the design of small projection optics. As a consequence the exit pupil of the projection lens is small and emits light with high luminance, which can be hazardous to the eye when staring into the projection lens.
Lasers could be considered to be ideal light sources for projectors as they act almost like a point source and therefore aim at light with extremely high luminance. However, projectors which use laser light sources must be classified according to laser safety standard IEC60825-1, and with state of the art optical architectures it is impossible to realize a projector which both has sufficient lumen output (e.g. output of 1000 lumen) and as well fulfills laser safety class 1 conditions. As a consequence, laser projectors are not common in everyday's use so far.